A common type of drive mechanism for an endless belt conveyor is mounted beneath the conveyor frame and includes a motor that drives a spindle or roller which is engaged with the lower run of the belt. The conventional drive mechanism can also include a movable tensioning spindle over which the belt is trained and by adjustment of the tensioning spindle, the tension on the belt can be controlled.
In a conventional drive mechanism which is mounted beneath a conveyor frame, the motor, the drive spindle, and the tensioning spindle are carried by a pair of side plates which are suspended from the side rails of the conveyor frame. To provide sufficient strength and rigidity, the side plates are normally formed of steel plate having a thickness of about 1/4 inch. To mount the motor, as well as the spindles to the side plates, the side plates are formed with a series of openings of various configurations, which are machined in the plates. The side plates are also formed with a substantial number of small holes which are drilled in the side plates for attachment of various components. Because of the extensive machining and drilling operations, the production of the side plates is extremely costly.